Muscle stimulating method and apparatus



Aug. 6, 1957 w. H. DE s1". CYR

MUSCLE STIMULATING METHOD AND APPARATUS Filed May 12, 1954 flVENToRi ATTORNEYS.

Uited States Patent MUSCLE STIMULATING METHOD AND APPARATUS William H. De St. Cyr, Chicago, ill.

Application May 12, 1954, Serial No. 429,209

Claims. (Cl. 128-369) This invention relates to a method of and apparatus for stimulating muscles of a subject person and is particularly, although not exclusively, applicable to procedures in which the body portion desired to be affected is immersed in a water bath.

Stimulation of the muscles in accordance with this invention is particularly appropriate and useful in cases in which the member to be stimulated is partially paralyzed or otherwise impaired.

One of the principal objects of the invention is to provide a muscle stimulating method and apparatus whereby vigorous motor action may be induced in a selected body member so that the member will be moved through a substantial range.

A further object is to provide a muscle stimulating method and apparatus effective to produce substantial movement and exercise of the selected body member.

A further object of the invention is to provide a muscle stimulating method and apparatus utilizing readily available alternating current rather than the special currents which have sometimes been employed in prior practices.

Another object is to provide a method of and apparatus for muscle stimulation which are not only highly effective but also safe and otherwise practicable.

Further objects and advantages of the invention will appear from the following description of an illustrative embodiment of the invention, when read in connection with the accompanying drawings, in which:

Figure 1 is a diagrammatic representation of exemplary muscle stimulating apparatus constructed in accordance with the invention;

Fig. 2 is a side elevational view, partly in section, of a rotary potentiometer embodied in the apparatus of Fig. 1;

Fig. 3 is a sectional view of the potentiometer taken generally along a line 33 in Fig. 2;

Fig. 4 is an elevational sectional view of a treatment tub and associated electrodes taken generally along a line 4--4 in Fig. 1; and

Fig. 5 is a fragmentary, partly sectional perspective view showing an exemplary construction for electrodes employed in the apparatus of Fig. 1.

Considered in greater detail, Fig. 1 illustrates a muscle stimulating apparatus comprising a tub 11 adapted to hold a water bath 12, as indicated in Fig. 4.. For safety, the tub is insulated by mounting it on a platform 14 made of insulating material. A mixing type water faucet 15 for supplying hot and cold water to the tub 11 is mounted above the tub in spaced relation thereto so as to avoid any electrical grounding of the tub. Likewise, the tub 11 is provided with an outlet drain l6 spaced substantially above a funnel 18 connected to the sewer so as to avoid any grounding by way of the drain.

At least two electrodes 20 are disposed in the water bath 12, and three such electrodes, marked 20a, 20b, and 200 for identification, are provided in the illustrated apparatus. The arrangement of the electrodes may be varied widely to provide simulation of various portions Patented Aug. 6, .1957

of a subject person, but as illustrated the electrode 201; is suspended from an insulating rod 21 placed across the front end of the tub so as to position the electrode above or between the feet of a subject person when sitting in the tub. The electrodes 2% and 20c are disposed adjacent the opposite end of the tub and are suspended from opposite sides thereof in positions generally opposite the subject persons body when sitting in the tub. In the present instance, the electrodes 20b and 20c are connected together electrically by means of a lead 22.

To energize the electrodes 20, the apparatus 10 is provided with a power unit 24 which itself is adapted to be energized from power lines 25 and 26 carrying ordinary alternating current at 60 cycles per second or any other commercial frequency. The alternating current may be at the conventional 115 volts or thereabouts. To isolate the electrodes 20 from conductive connection to the power lines 25 and 26, the power unit 24 preferably is provided with a transformer 28 having primary and secondary windings 29 and 30. The terminal leads of the primary winding 29 may be connected to the power line wires 25 and 26. A control switch 31 may be connected in series with one line wire 25 to provide selective control of the energization of the power unit 24. The transformer 28 may be made with a stepup or step-down ratio to provide any desired treatment voltage, but it is suitable to provide a transformer having a 1:1 ratio so that the secondary and primary voltages are the same.

In order to vary the output of the power unit 24 in rhythmic fashion, a power operated control device 32 is connected to the transformer secondary 30. The control device 32 may assume a variety of forms but is illustrated as comprising a rotary potentiometer 34 (Figs. 1-3) adapted to effect a generally sinusoidal variation in the amplitude and phase polarity of the alternating output from the power unit 24. Generally, the potentiometer 34 comprises a resistance element 35 connected across the transformer secondary 30. A pair of sliding contacts or brushes 36 and 37 are arranged to be moved in opposite directions back and forth along the resistance element 35 from end to end thereof. In the form illustrated in Figs. 2 and 3, such movement is imparted to the brushes 36 and 37 by rotating them on the resistance element 35, which assumes the form of a winding 39 of resistance wire wrapped around a flat rectangular insulating plate 40. The brushes 36 and 37 are mounted on diametrical arms 41 secured to a rotatable shaft 42. Slip rings 43 and 44 are also mounted on the shaft 42 and are electrically connected to the brushes 36 and 37. The slip rings 43 and 44 are engaged by brushes 45 and 46.

When the brushes 36 and 37 are both. positioned over the middle turns of the resistance winding 39, as shown in Fig. 3, the voltage between the brushes is zero, but when the brushes are rotated through degrees so that they are adjacent the end points of the winding, the voltage is at a maximum and is substantially equal to the total voltage across the winding. For each half revolution of the shaft 42, the phase polarity of the voltage between the brushes is reversed.

To rotate the potentiometer shaft 42 at a proper speed, the shaft is in this instance connected to an electric motor 48 through shiftable speed reduction gearing 49. The motor 48 is energized by means of leads 49 and 50 connected to the power line wires 25 and 26 through the control switch. Thus the motor 48 is energized whenever the transformer 28 is supplied with voltage.

To provide for manual variation of the output voltage from the power unit 24, a potentiometer 52 is connected to the output brushes 45 and 46 of the rotary potentiometer 34. The potentiometer 52 comprises a resistance element 53 connected across the brushes 45 and 46. The

' resistance element is engaged by a rotatable slider 54.

The power unit 24 is equipped with a pair of output terminals 56 and 57 connected between the slider 5 and one end of the potentiometer 52. A pilot lamp 58 is connected across the output terminals 56 and 57 to provide a rough indication of the voltage at this point.

It will be understood that the potentiometer 52 may be connected in the circuit at any point between the power line wires 25 and 26 and the output terminals 56 and 57.

In the illustrated muscle stimulating apparatus, the

electrodes 20 are energized by being connected to the output terminals 56 and 57. The electrode 20a is connected to the terminal 56 while the interconnected electrodes 20b and 200 are connected to the output terminal 57. i As shown in Fig. 5, each of the electrodes may comprise a metal plate or sheet.60 sandwiched between a pair of insulating sheets 61 to prevent direct electrical contact between the body of the subject person and the metallic plate 60. Openings 62 are provided in the insulating sheets 61 to expose the plate 60 over a considerable area to the water bath 12.

In operating the apparatus of Fig. 1 in accordance with the method of this invention, the subject person for whom muscle stimulation is desired is seated or otherwise positioned in the tub 11. The depth of the Water bath 12 is adjusted to immerse the body member for which stimulation is desired. Initially, the potentiometer 52 may be adjusted manually so that only a small amount of voltage will appear at the output terminals 56 and 57 of the power unit 24. The electrodes 20 are arranged in the tub so that the current in the water bath will affect the member to be stimulated.

' To energize the power unit 24, the control switch 31 is closed. As a result, voltage is applied to the transformer primary 29 and the motor 48. Through the gear drive 49, the motor 43 rotates the shaft 42 and brush carrier arms 41 of the rotary potentiometer 34. Accordingly, the brushes 36 and 37 are moved in opposite directions from end to end along the length of the resistance element 35. When the brushes are both adjacent the midpoint of the resistance element 35, the voltage between the brushes will be substantially zero. As the brush carrier arms 41 are rotated through 90 degrees the voltage between the brushes rises to a maximum point which is reached when the brushes are adjacent the opposite ends of the resistance element 35. Further rotation of the brushes again reduces the voltage to zero and then reverses the phase polarity of the voltage. After 270 degrees of rotation, another maximum point is reached, following which the voltage again drops until the brushes return to their original positions. This cycle is repeated as long as the switch 31 remains closed. The phase polarity is reversed for each half revolution of the brushes 36 and 37.

With the manually operable potentiometer 52 adjusted to provide a suitable voltage between the electrodes 20a and the interconnected electrodes 20b and 200, the rising and falling and the phase reversal of the voltage, resulting from the operation of the power actuated control device 32, has the effect of inducing definite motor action in the muscles exposed to the currents in the Water bath 12, Definite contractions and relaxations of the muscles are produced so that the body member being stimulated is moved through a substantial distance corresponding as closely as possible to its full range of normal movement.

. This result of inducing definite and substantial motor action has not been achieved with any known prior method utilizing alternating current. With the known prior methods, only muscle twitching and slight tickling sensations were achieved at best. With the method of the present invention, however, the alternating current effectively moves the members of the subject person through a wide range. Accordingly, the muscles of the stimulated member are given etfective exercise.

The manually operable potentiometer 52 may be adjusted to provide suflicient voltage at the output terminals 56 and 57 to achieve the desired range of movement of the body member being stimulated. The pilot lamp 58 shows the rising and falling of the output voltage, due to the operation of the power actuated control device 32, and provides a rough indication of the magnitude of the voltage.

The speed at which the rotary potentiometer 34 is driven may be varied over a considerable range, but, for example, a speed of about ten to twelve revolutions per minute is suitable in most cases. This speed in most cases will correspond generally to the normal breathing rate of the subject, and such a corresponding relation is generally desirable.

The apparatus of the present invention maybe extremely compact and light in weight and, hence, may be readily portable. This is in marked contrast with the heavy and cumbersome prior apparatus employed in this field.

It will be evident that various modifications, equivalents and alternative constructions may be employed without departing from the true spirit and scope of the invention as set forth in the specification and drawing and defined in the appended claims.

I claim:

1. A method of inducing motor action in muscles of a selected body portion, comprising the steps of immersing the selected portion in a water bath, passing a substantially sinusoidal alternating electric current through the bath adjacent the selected portion, and rhythmically reversing the phase polarity and varying the magnitude of said current at a slow rate compared with the frequency of the alternating current.

2. Muscle stimulating apparatus for inducing motor action in muscles of a subject, comprising a tub for holding a water bath, said tub being of a size adequate to immerse an entire adult human body, exclusive of the head thereof, first and second electrodes in said tub for immersion in said water bath, an electrical energizing device having a pair of output leads connected to said first and second electrodes, said device including means connected to said electrodes for supplying a substantially sinusoidal alternating current thereto and power means connected to said last mentioned means for rhythmically varying the magnitude and phase polarity of said current at a slow rate. compared with the frequency of the alternating current, to induce rhythmic muscle action in the subject.

3. A muscle stimulating apparatus for inducing motor action in muscles of a subject, comprising a tub for holding a water bath, first, second, and third electrodes in said tub for immersion in said water bath, said first electrode being disposed adjacent one end of said tub, said second and third electrodes being disposed adjacent the opposite end of said tub at opposite sides thereof, means connecting said second and third electrodes together electrically, an electrical energizing device having a pair of output leads connected to said first electrode and said interconnected second and third electrodes, said device including a transformer having primary and secondary windings, circuit means connected to said primary winding and adapted to be connected to a source of alternating current for supplying said primary winding with a1ternat ing current, a potentiometer connected between said secondary winding and said output leads for supplying a variable alternating voltage thereto, and a motor drivingly connected to said potentiometer for operating said potentiometer to vary the magnitude and phase polarity of saidvoltage generally sinusoidally in rhythmic fashion at a rate corresponding generally to the normal breathing rate of the subject, said device having manually controllable means for adjusting the amplitude of said voltage.

4. A muscle stimulating device for inducing motor action in muscles of a subject, comprising a potentiometer having a conductive element and a pair of sliders contacting said element, transformer means having a secondary winding connected to said element and having a primary winding connected to a source of substantially sinusoidal alternating current for supplying said element with alternating current, output connecting elements connected to said sliders, a motor, and means operable by said motor foreffecting relative cyclical movement between said element and said sliders and thereby provid ing a voltage varying rhythmically in magnitude and phase polarity across said output elements.

5. A muscle stimulating device for inducing motor action in muscles of a subject, comprising a transformer having primary and secondary windings, a substantially sinusoidal source of alternating current connected to said primary winding for supplying said primary winding with alternating current, a potentiometer connected across said secondary winding, said potentiometer having a pair of sliders, a motor, means operable by said motor for moving said sliders along said potentiometer winding to provide a voltage between said sliders having rhythmically varying magnitude and phase polarity, a pair of output connecting elements, and a manually adjustable potentiometer connected between said sliders and said output elements for adjusting the magnitude of the voltage across said elements.

References Cited in the file of this patent UNITED STATES PATENTS 584,957 Patten June 22, 1897 647,006 Maggiorani Apr. 10, 1900 1,338,269 Wappler Apr. 27, 1920 1,487,837 Bueckle Mar. 25, 1924 1,514,746 Wappler Nov. 11, 1924 1,858,104 Miles May 10, 1932 2,532,788 Sarnofl? Dec. 5, 1950 2,664,880 Wales, Jr. Jan. 5, 1954 FOREIGN PATENTS 428,953 Great Britain May 22, 1935 

